In the discussion that follows, reference is made to certain structures and/or methods. However, the following references should not be construed as an admission that these structures and/or methods constitute prior art. Applicant expressly reserves the right to demonstrate that such structures and/or methods do not qualify as prior art.
Amides of acrylic or methacrylic acid are known as comonomers for the preparation of polymers for prostheses (GB-A-1 039 750) or denture adhesives (DE-A-2 316 603, U.S. Pat. No. 3,926,870, U.S. Pat. No. 5,011,868). Furthermore, selectively substituted acrylamides or methacrylamides are suitable as effective adhesion components in dental adhesives, which for example are the subject of U.S. Pat. No. 3,660,343 or EP-A-0 394 792 or have been described by S. Kitoh et al (cf. J. Appl. Polym. Sci. 39 (1990) 103, J. Appl. Polym. Sci. 51 (1994) 2021). Finally, because of their improved hydrolysis stability compared with conventional dimethacrylate cross-linkers, multifunctional (meth)acrylamides are particularly suitable as cross-linkers for aqueous-acid enamel-dentine adhesives (cf. N. Moszner, F. Zeuner, J. Angermann, U. K. Fischer, V. Rheinberger, Macromol. Mater. Eng. 288 (2003) 621; U.S. Pat. No. 6,953,832) and also for self-adhesive composites (cf. N. Moszner, U. K. Fischer, J. Angermann, V. Rheinberger, Dent. Mater. 22 (2006) 1157).
N-alkoxy-N-alkylamides, also called Weinreb amides, are intermediate products established in modern organic synthesis chemistry, e.g., for the synthesis of sterically demanding ketones or as substrate for enantioselective Diels-Alder reactions (M. Mentzel, H. M. R. Hoffmann, J. prakt. Chem. 330 (1997) 517). Weinreb amides can be accessed easily, e.g., by acylation of N,O-dimethylhydroxylamine with the corresponding acid chloride. The Weinreb amides are also characterized by a considerable stability and can accordingly be purified by customary methods, e.g., by crystallization, distillation or chromatography. Above all the N-methoxy-N-methyl acrylamide is known as polymerizable N,O-functionalized carboxylic acid hydroxamide (cf. U. K. Fischer, N. Moszner, F. Zeuner, V. Rheinberger, Tagungsband der GDCh-Fachgruppentagung Polymers & Coatings (conference booklet of the German Chemical Society), Sep. 24-26, 2006, Mainz, p. 82). On the other hand, the use of polymerizable, N,O-functionalized acrylic acid hydroxamides for the preparation of dental materials is not described.